The city Department of Investigation announced it was looking into why officials didn’t report a beat-down by security guards.

The city Department of Investigation Tuesday announced it was looking into why homeless agency officials didn’t tell them about a beat-down by security guards inside a city shelter.

The Daily News revealed Tuesday two security guards and a supervisor working for a private firm were involved in a Nov. 29 attack on a homeless man inside the Pamoja Men’s Shelter in Bedford-Stuyvesant.

In the attack, captured on video, a guard kicks the man in the face and stomps on his body. Two homeless residents also hit the man while he’s down, and a supervisor for the firm, FJC Security, does little to intervene.

In response to the report, DOI spokeswoman Diane Struzzi said Tuesday, “DHS did not notify DOI about the assault by FJC Security and should have. DOI is looking into this matter.”

The DOI Commissioner Mark Peters (pictured) was asked to look into the incident at the Pamoja Shelter and called for increased scrutiny of shelter safety. (Jefferson Siegel/New York Daily News)

On Tuesday DHS spokesman Isaac McGinn did not respond to questions about DOI’s inquiry, but said after agency officials learned of the incident, they made sure the security personnel involved no longer worked in city shelters.

“The two individuals demonstrably abused their authority and mistreated our clients, and we had all the evidence we needed to remove them,” he said.

The News reported that FJC and another firm, Sera Security, have been sued 21 times in the last three years over incidents of shelter violence. The firms aren’t hired by the city but by non-profit groups the city pays to run shelters.

Security staff (FJC Security) seen in a still of surveillance footage punching and kicking a homeless man inside the Brooklyn shelter. (Courtesy of Lipsig Shapey Manus & Moverman)

As a result, DHS has little direct oversight over the behavior of the firms.

On Tuesday Council Oversight Committee Chairman Ritchie Torres asked DOI Commissioner Mark Peters to look into the incident at the Pamoja Shelter and called for increased scrutiny of shelter safety.

“By outsourcing to the wild wild west of security subcontractors, the city is taking an arms-length approach to security,” Torres told The News. “It’s especially egregious when the safety of New Yorkers is at stake.”

In his letter to Peters, Torres said he’ll propose legislation requiring full disclosure of information regarding the hiring of private security firms, the procurement protocols and the ultimate cost to taxpayers.

Torres said he was troubled by The News’ revelation that security at almost all of these city shelters is performed by only the two much-sued vendors, FJC and Sera.

“The security of the shelter system is in the hands of a dubious duopoly subsidized by the public,” he wrote. “The lack of oversight over these security subcontractors reflects the City’s continuing complacency about the safety of the municipal shelter system.”

The News revealed last month that DHS has hidden from the public hundreds of arrests at city-run shelters, prompting the state Office of Temporary & Disability Assistance to demand full disclosure.

After that report, the city began revealing shelter arrest data to OTDA and disclosed the overall number of arrests in the system for the first three months of this year — 674.